Question: Tiffany had to do problems 43 through 69 for homework last week. If Tiffany did all of the problems she was assigned, how many problems did she do?
Answer: Instead of counting problems 43 through 69, we can subtract 42 from each number so we instead consider problems 1 through 27. We see that Tiffany did 27 problems. Notice that she did 27 and not 26 problems.